Best Exchange Rate API in 2026: 10 Providers Compared Honestly

The 10 best exchange rate APIs in 2026, compared on real free-tier limits, update frequency, HTTPS, base currency, historical data and official central-bank tables: AllRatesToday, Frankfurter, ExchangeRate-API, Open Exchange Rates, Fixer, currencylayer, CurrencyAPI, ExchangeRatesAPI.io, XE and Global Exchange Rates.

By Madhushan, Founder & Lead Developer

There are dozens of exchange rate APIs and most look identical until you ship with one. Then the differences show: a free tier that is HTTP-only, "real-time" that means hourly, a base currency you cannot change without paying, historical data that costs extra, or a market rate where your accountant needed the central bank's figure. This guide compares the ten providers developers actually shortlist, on the details that decide the choice.

Disclosure: AllRatesToday publishes this guide and is ranked first. Every figure below comes from the provider's public pricing or documentation page, last checked on 2026-09-14. Free tiers change often, so confirm on the vendor's site before you commit.

Quick comparison

Test one in thirty seconds

Two of the ten need no account. This returns the European Central Bank's reference rate with its publication date, which is the quickest way to see what "official rate" means in practice:

curl "https://allratestoday.com/api/open/central-bank/ecb?source=USD&target=EUR"
# {"bank":"ecb","rate_date":"2026-09-12","source":"USD","target":"EUR","rate":0.8626,"rate_type":"reference","derived":false,...}

1. AllRatesToday

Best for: teams that need both kinds of rate. Real-time mid-market quotes for 160+ currencies refresh every 60 seconds, and the same key serves the official tables of 121 central banks and the HMRC, US Treasury and Swiss customs authorities, each with the publisher's own date. The official endpoint is keyless. Details on the exchange rate API page.

2. Frankfurter

Best for: open-source and internal projects that only need daily central-bank fixings.

Read the Frankfurter comparison if you need more than daily.

3. ExchangeRate-API

Best for: dashboards and reports that need volume and can live with a daily snapshot.

See the ExchangeRate-API comparison.

4. Open Exchange Rates

Best for: teams that want a long-established vendor and accept hourly data.

See the Open Exchange Rates comparison.

5. Fixer.io

Best for: teams already on the apilayer marketplace who want one bill.

See the Fixer comparison.

6. currencylayer

Best for: the same apilayer stack with a USD base instead of EUR.

See the currencylayer comparison.

7. CurrencyAPI

Best for: small projects that value a clean dashboard over a large quota.

See the CurrencyAPI comparison.

8. ExchangeRatesAPI.io

Best for: integrations written before it joined apilayer; there is little reason to start on it now.

See the ExchangeRatesAPI.io comparison.

9. XE Currency Data API

Best for: banks and large fintechs that need a recognised vendor on an annual contract.

See the XE comparison.

10. Global Exchange Rates

Best for: accounting teams that want official rates only and are fine with a trial rather than a free tier.

See the Global Exchange Rates comparison.

How to pick

• Checkout, price display, converters: a real-time market rate. AllRatesToday, or Open Exchange Rates if hourly is enough.
• Invoices, VAT, customs, audit: the official rate of a named institution with its date. AllRatesToday or Global Exchange Rates; Frankfurter if the ECB alone covers you.
• Reports and dashboards on a budget: ExchangeRate-API's daily free tier, or the free central-bank archives on Hugging Face.
• Regulated enterprise with procurement: XE.
• Python, Node or another specific stack: the language guides for Python, JavaScript, PHP and Go cover SDK quality per provider.

How we compared

Each provider's public pricing page and documentation were checked on 2026-09-14 for the free tier's request allowance, transport, base-currency restriction, update frequency and historical access, then whether the rates are a market blend or a named institution's published table. Nothing here is based on private benchmarks. Where a vendor does not publish a figure the table says so rather than guessing.

Frequently asked questions

What is the best free exchange rate API?

For daily official fixings with no key, Frankfurter. For the largest free quota of market rates, ExchangeRate-API at about 1,500 requests a month with daily updates. For real-time rates on a free key with HTTPS and any base currency, AllRatesToday, which also serves the latest table of 121 central banks with no key at all.

Which exchange rate API updates in real time?

AllRatesToday refreshes mid-market rates every 60 seconds on every plan including free. Open Exchange Rates, Fixer and currencylayer update hourly on lower tiers. ExchangeRate-API and Frankfurter update once a day. XE quotes real-time data on enterprise contracts.

Which exchange rate API is best for accounting, VAT or customs?

Use one that serves the official rate a named institution published, with the publication date, rather than a market rate. AllRatesToday covers 121 central banks and the HMRC, US Treasury and Swiss customs tables. Frankfurter and Global Exchange Rates also serve official fixings. Market-rate APIs such as Open Exchange Rates or Fixer are not the figure a tax return asks for.

Do free exchange rate APIs allow commercial use?

Mostly no, or only with attribution. Fixer, currencylayer and ExchangeRatesAPI.io restrict the free plan to non-commercial use. ExchangeRate-API requires attribution on its open endpoint. AllRatesToday allows commercial use on paid plans from €4.99 a month and requires attribution for public displays on the keyless endpoint.

How do I test an exchange rate API without signing up?

Frankfurter and the AllRatesToday official-rate endpoint need no key. For example, a GET to allratestoday.com/api/open/central-bank/ecb with source and target parameters returns the ECB reference rate as JSON with the publication date.

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